Structure and method for mounting a photovoltaic material

Abstract

A photovoltaic device is adhesively mounted to a support structure such as a roofing member or building panel by the use of a body of foamed adhesive. The foamed adhesive is resilient and accommodates differences in the thermal expansion and contraction of materials comprising the photovoltaic device and the structure upon which it is mounted and thereby prevents delamination and other stress-related damage to the photovoltaic installation. The adhesive may comprise a contact adhesive, a hot melt adhesive, or a curable adhesive. Further disclosed are methods for affixing photovoltaic systems to building structures and the like through the use of foamed adhesives.

1 . An adhesively affixable photovoltaic member comprising:
 a photovoltaic device including a body of a photovoltaic semiconductor material which operates to absorb incident photons and generate an electrical current in response thereto, said photovoltaic device further including a substrate having said body of photovoltaic semiconductor material supported upon a first face thereat and   a body of a foamed adhesive supported on a second face of said substrate opposite said first face; wherein said foamed adhesive is operative to bond said photovoltaic device to a support member while accommodating the differential thermal expansion of said photovoltaic device and said support member.   
     
     
         2 . The photovoltaic member of  claim 1 , wherein said foamed adhesive is a contact adhesive. 
     
     
         3 . The photovoltaic member of  claim 1 , wherein said foamed adhesive is a curable adhesive. 
     
     
         4 . The photovoltaic member of  claim 1 , wherein said adhesive is a hot melt adhesive. 
     
     
         5 . The photovoltaic member of  claim 1 , further including a removable body of a release material adhered to said adhesive layer. 
     
     
         6 . The photovoltaic member of  claim 1 , wherein the void volume of said foamed adhesive is in the range of 5-80 percent. 
     
     
         7 . The photovoltaic member of  claim 6 , wherein said void volume is in the range of 40-50 percent. 
     
     
         8 . The photovoltaic member of  claim 1 , wherein said foamed adhesive has an at least partially closed cellular structure. 
     
     
         9 . The photovoltaic member of  claim 8 , wherein foamed adhesive has a partially closed cellular structure in which the void volume of the closed cells is in the range of 10% to 40% 
     
     
         10 . The photovoltaic member of  claim 1 , wherein the foamed structure of said adhesive is provided by a plurality of gas bubbles dispersed therein. 
     
     
         11 . The photovoltaic member of  claim 10 , wherein said gas bubbles comprise a gas selected from the group consisting of: air, nitrogen, argon, helium, a fluorocarbon, and combinations thereof. 
     
     
         12 . The photovoltaic member of  claim 1 , wherein the foamed structure of said adhesive is defined by a plurality of hollow microspheres dispersed therein. 
     
     
         13 . The photovoltaic member of  claim 1 , wherein said body of foamed adhesive has a thickness of at least 0.5 millimeters. 
     
     
         14 . The photovoltaic member of  claim 1 , wherein said photovoltaic device comprises a body of a thin film semiconductor material and said substrate comprises a metal. 
     
     
         15 . The photovoltaic member of  claim 1 , wherein said photovoltaic device includes a transparent encapsulant layer disposed on a light-incident side of said photovoltaic device. 
     
     
         16 . The photovoltaic member of  claim 1 , wherein said substrate includes a layer of an encapsulant material covering the second face thereof, and wherein said body of foamed adhesive is disposed atop said layer of encapsulant material. 
     
     
         17 . A photovoltaic installation comprising:
 a support member;   at least one photovoltaic device; and   a foamed adhesive which adhesively affixes said at least one photovoltaic device to said support member.   
     
     
         18 . The photovoltaic installation of  claim 17 , wherein said support member is a building structure. 
     
     
         19 . The photovoltaic installation of  claim 17 , wherein said support member is a roofing membrane. 
     
     
         20 . A method for affixing a photovoltaic device to a support member, said method comprising adhesively affixing said photovoltaic device to said support member with a body of a foamed adhesive.